Home entertainment systems have been provided that can include a set-top box media server that communicates with various components in the home, e.g., TVs, laptop computers, and custom display devices. To establish network communication paths, power line communication (PLC) networks have been introduced and have gained in popularity owing to the fact that the home's existing AC power grid is used to also carry entertainment data between various components in the home entertainment system which are plugged into AC wall sockets.
Among the current advances in PLC networking is audio streaming, in which an audio adapter having a pair of conventional analog audio input and output terminals can interconnect a source of audio, for example a CD player, to powered stereo speakers located in various rooms of the home. The user thus can listen to music from the CD player at any AC outlet. Also, the above-mentioned product can broadcast an audio stream, with two or more clients simultaneously receiving the same stream from the server so that the user can listen to music in any room in the home.
As recognized herein, while useful, the above home entertainment audio subsystem suffers from the drawback of not having an adequate synchronization mechanism between client speakers. Even when two client speakers start decoding the audio data at the same time, a delay can exist between them and can gradually grow larger over time. When the delay approaches or exceeds around thirty milliseconds, the human ear detects an echo effect that diminishes the listening pleasure.
The present invention further recognizes that simply broadcasting clock information from the server to the various home entertainment system clients is less than an optimal solution because of a lack of accuracy. For example, using Network Time Protocol principles, the difference between clocks of client devices can approach one hundred milliseconds. With the above critical recognition in mind, the invention herein is provided.